Optical processing of materials

Abstract

Abstract 1371624 Perforating and welding by fusion UNITED KINGDOM ATOMIC ENERGY AUTHORITY 21 March 1972 [26 March 1971] 7983/71 Headings B3V and B3R [Also in Division G2] An apparatus for optically processing a workpiece 7 comprises a cylinder 6 for receiving a workpiece 7, means 5 for focusing a beam of light 2 from a stationary source 1 on to the workpiece 7, means for rotating and translating the cylinder 6 relative to the light beam 2, means 11 for interrupting the light beam 2 and means for varying the phase relationship between the rotation of the cylinder 6 and the interruptions of the light beam 2. The apparatus may be used for welding or perforating using a laser beam, for producing local variations in the dyeability of fabrics and for making masks by a photolithographic process using an ultra-violet or visible lamp. In the embodiment described, the workpiece 7 is mounted on a drum 6 on to which a laser beam 2 from a CO 2 laser 1 is focused by a water cooled lens 5. The drum 6, which is supported by rollers 16, 17, Fig. 2, in a carriage 15, is rotated by a motor 26, via a shaft 27, toothed belts 28 and pulleys 29, and simultaneously translated along rails 24, 25 by engagement of a rack 32 with a pinion 30 which is driven from the shaft 27. A slotted disc 11 in the path of the laser beam 2 is rotated by a motor 12 so that a desired pattern of perforations is produced in the workpiece 7 The disc 11 and drum 6 may be rotated in synchronism or out of phase to vary the pattern of perforations by mechanically rotating the motor 12 in a mounting (40) (Fig. 3, not shown) by means of a cam (34) which is rotated from the motor 26 and which reciprocates a rod (37) to cause rotation of a gear-wheel (38) meshing with a gear wheel (39) on the motor casing. The power of the beam 2 is monitored by a detector 14 and a device for modulating the beam intensity may be provided in order to vary the size or occurrence of the holes. The beam 2 is passed through an asbestos sheet 4 and may be deflected by a mirror 9. A larger pattern may be superimposed on the pattern of perforations produced by using a mask (41) (Fig. 4, not shown) positioned on the workpiece.

Inventors

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